Human and rat gamma glutamyl hydrolase genes

Abstract

The present invention is directed to isolated nucleic acid molecules encoding gamma glutamyl hydrolase (GH). Expression vectors and host cells comprising the nucleic acid molecules are also provided, as well as methods for increasing or decreasing the expression of GH in host cells. The invention further provides a method of screening a substance for the ability of the substance to modify GH function, and a method for isolating other GH molecules. DNA oligomers and antibodies specific for GH are provided, each of which can be used to detect GH in a sample. Methods for decreasing deleterious side effects of antifolate treatment, increasing the levels of GH in cells of a patient, increasing the effectiveness of antifolate treatment, and monitoring progression of a tumor are further provided.

What is claimed is: 
     
       1. An isolated nucleic acid molecule encoding an intracellular human or rat gamma glutamyl hydrolase. 
     
     
       2. The isolated nucleic acid molecule of claim 1 wherein said nucleic acid is deoxyribonucleic acid. 
     
     
       3. The isolated nucleic acid molecule of claim 2 wherein said deoxyribonucleic acid is cDNA. 
     
     
       4. The isolated nucleic acid molecule of claim 1 wherein said gamma glutamyl hydrolase is a human gamma glutamyl hydrolase. 
     
     
       5. An isolated nucleic acid molecule encoding an intracellular human gamma glutamyl hydrolase wherein said nucleic acid molecule encodes an amino acid sequence as shown in SEQ ID NO:2. 
     
     
       6. The isolated nucleic acid molecule of claim 5 wherein said nucleic acid molecule has a nucleotide sequence as shown in SEQ ID NO:1. 
     
     
       7. The isolated nucleic acid molecule of claim 1 wherein said gamma glutamyl hydrolase is a rat gamma glutamyl hydrolase. 
     
     
       8. An isolated nucleic acid molecule encoding a rat gamma glutamyl hydrolase wherein said nucleic acid molecule encodes an amino acid sequence as shown in SEQ ID NO:4. 
     
     
       9. The isolated nucleic acid molecule of claim 8 wherein said nucleic acid molecule has a nucleotide sequence as shown in SEQ ID NO:3. 
     
     
       10. The isolated nucleic acid molecule of claim 1 wherein said nucleic acid is ribonucleic acid. 
     
     
       11. The isolated nucleic acid molecule of claim 10 wherein said ribonucleic acid is mRNA. 
     
     
       12. A nucleic acid oligomer of about 20 to about 45 nucleotides complementary to the mRNA of claim 11. 
     
     
       13. A cell comprising the nucleic acid molecule of claim 1. 
     
     
       14. The cell of claim 13 wherein the cell is a bone marrow cell. 
     
     
       15. An expression vector comprising the nucleic acid molecule of claim 1. 
     
     
       16. The expression vector of claim 15 wherein said expression vector is selected from the group consisting of a plasmid and a virus. 
     
     
       17. A cell comprising the expression vector of claim 15. 
     
     
       18. The cell of claim 17 wherein the cell is a bone marrow cell. 
     
     
       19. A method of increasing production of gamma glutamyl hydrolase in a host cell, said method comprising: introducing the nucleic acid molecule of claim 1 into the cell; and   allowing said cell to express said nucleic acid molecule resulting in the production of gamma glutamyl hydrolase in said cell.   
     
     
       20. The method of claim 19 wherein the cell is a bone marrow cell. 
     
     
       21. A method of screening a substance for the ability of the substance to modify gamma glutamyl hydrolase function, said method comprising: introducing the nucleic acid molecule of claim 1 into a host cell;   expressing said nucleic acid molecule in the host cell so as to produce gamma glutamyl hydrolase;   exposing the cell to a substance; and   evaluating the exposed cell to determine if the substance modifies the function of the gamma glutamyl hydrolase.   
     
     
       22. The method of claim 21 wherein the cell is selected from the group consisting of bone marrow progenitor cells, rat liver tumor cells, human breast cancer cells, human leukemia cells, human colon cancer cells, and human prostate cancer cells. 
     
     
       23. The method of claim 21 wherein said evaluation comprises monitoring the production of gamma glutamyl hydrolase. 
     
     
       24. The method of claim 21 wherein said evaluation comprises monitoring hydrolysis of antifolylpolyglutamates by said gamma glutamyl hydrolase. 
     
     
       25. The method of claim 21 wherein said substance is a peptide or small molecule that blocks gamma glutamyl hydrolase hydrolysis of antifolylpolyglutamates. 
     
     
       26. A nucleic acid oligomer of about 20 to about 45 nucleotides complementary to the nucleic acid molecule of claim 1.